December 1, World Aids Day. is a day when citizens of the world are invited to consider the impact of the modern day scourge of HIV infection and what is being done to control and conquer the disease. This year, the focus is on the two populations most vulnerable to AIDS worldwide - young women and children.

For more than 15 years, the Adolescent AIDS program at the Children's Hospital at Montefiore in New York City has been treating young people from ages 12 to 24 infected with HIV with medicines and emotional and community support. It is a small, comfortable facility in a decidedly first world locale. But program director and pediatrician Donna Futterman says that like their counterparts in the developing world, New York adolescent girls and young women are far more likely to be infected with the virus than adolescent boys and younger men.

"In fact, the peak age of infection for young women is five to ten years younger than it is for males," she said. "There are several reasons to account for this. The first is that younger women frequently have older partners, young women can be victims of sexual violence, young women in many cultures around the world are not empowered to make choices about who they are going to have sex with. Historically throughout the world, women have sex with older partners, and the rate of HIV infection among older men is higher and [so] their [female partners'] risk of running into this is higher."

Denise, 26, is an HIV-positive New Yorker with a steady job and a fairly happy life. But she was only 12 years old in 1990 when she learned she had contracted the disease. Unlike today, that was an era when HIV usually meant death - and soon. She remembers the loneliness and terror she felt before coming to the Adolescent AIDS program.

"And I automatically assumed I was going to die after receiving the diagnosis. I didn't have a support system and it was just devastating for me because I wasn't living at home; I was living in foster care and I was just alone. But once I learned that people can live a long time with HIV, then I started to realize that maybe I do have a chance of living a long and healthy life with this virus," she said.

Among the ways girls like Denise contract the AIDS virus is that they are forced to have sex, or fall under the sway of an older man and not know how to safely refuse his sexual advances. Denise says women all over the world must gain the skills and confidence to assert control.

"It's very difficult being a woman in any country because men run things," she said. "I think it is very important as a woman, as a girl [and] as a female, that you empower yourselves with the knowledge and the tools so you can go out there and be productive in society and not have to wait on a man to do anything for you and make those decisions that could possibly lead you to having HIV. You have the option to say no. You have the option of getting birth control. You have the option of using a condom because it is your life."

Very young children, of course, cannot make the choices that could prevent HIV infection. Most contract the virus from their mothers while in the womb.

"Children are extremely vulnerable to HIV if their mother has HIV, doesn't know it and doesn't take medicine; one of four of them will be born with this," Dr. Futterman said. "Luckily, many of them are surviving childhood even into adolescence. But they've grown up with this disease hanging over their heads.

Yet millions of children who have not contracted HIV still suffer its effects when their parents die of the disease. It is a global problem with huge social and economic consequences.

Dr. Futterman says she has high hopes that the progress that's been achieved in the battle against HIV AIDS can be extended to parts of the world that are still waiting for effective treatments. "One of our intense goals is that we can learn to share the bounties of treatment that we have in the United States and the Western world with other underdeveloped throughout the world, so that anywhere in the world that someone is infected with HIV they have the chance for treatment and a long life.

We also have a lot we can learn from other people. When I travel and work in Africa, I see they are more advanced in many ways than we are here in the United States. So viewing this as a one world problem, we can all learn from each other's approaches," she said.